Friday, October 10, 2014

Rome Wasn't Built In A Day, And Neither Was My Studio

Back in 2011, I built myself a humble studio, and after having painstakingly labored to get the acoustics to my satisfaction (see here), I recently did something crazy: I changed everything.

This was not a case of me having a sickness. Nor do I particularly enjoy torturing myself, as “tuning” a room can be very tedious and frustrating work. No, this was about the never-ending quest for superior acoustics. You see, I wanted to get new speakers and a 2nd subwoofer, but the problem was that I would not be able to integrate them into the existing setup. So I had a choice to make: either maintain the status quo, or uproot my existing setup. Well, to hell with the status quo!

Let’s proceed like a movie that shows you the ending first, and then jumps back to the beginning. This is the new studio:

This is the old studio:

In comparing the before and after you will notice, A) the orientation within the room has changed, B) a window has magically appeared, and C) there’s less acoustic treatment in the room (about half as much). The change in orientation was mainly a practical one - with larger speakers, and more of them, changing the orientation better accommodated all the pieces of the puzzle. As for the window, it was always there but previously it was boarded up with a custom-made panel in order to create a continuous and uniform wall surface (and it was completely obscured by acoustic treatment). In the old setup the room measured better with the panel in the window, but in the new orientation it measured better without it. Wonderful...now I get to be exposed to actual daylight during the day!

For those unfamiliar with this topic, when I refer to measuring a room, I’m talking about measuring the frequency response of the room - i.e., how sound propagates throughout the space and collects at the listening position. This is achieved by setting up a microphone to record the dispersement of sound emitted from the speakers - then that recording gets analyzed by acoustic software and presented as a set of data, which can be used to make comparisons.

You might be wondering, how could I possibly achieve equal acoustic results using half the amount of acoustic treatment? The truth is, I don’t have equal results…I have better results. This miraculous feat was achieved through a combination of factors.

To start with, much of the acoustic battle can be waged with strategic placement of the speakers and listener. As you change the position of the speakers, you change the way the room is excited and the way in which sound reflects off the walls, which affects the resulting sonics at the listening position. And as you change the listening position, the amalgamation of those reflections that reach the listener are altered.

In the old room, the speakers were on console shelves. This meant that the main speakers and the listener could only be moved together as a single unit, thus limiting the potential acoustic progress you can make using positioning alone. With the new speakers on dedicated stands, now the speakers and listener could be independently moved, allowing more progress to be made. In addition, adding a 2nd subwoofer into the equation provides further flexibility, as there are more placement possibilities with two subs compared to one (as well as other acoustic benefits), thus allowing even more progress to be made.

So the first thing that needed to be done was to remove all of the existing room treatment, which resulted in a room that looked like this:

And a garage that looked like this:

Swap out the old speakers for the new speakers, bring in the additional sub, and let the games begin. In the end, with more possibilities for speaker / listener placement in the new studio, more acoustic issues were able to be addressed with calculated positioning, which meant there was less heavy lifting that needed to be done using acoustic treatment. But make no mistake, there was still lifting to be done. Enter Modex Plates.

Modex plates are pressure-based traps that get flush mounted to a wall surface. I had never used such treatment before, but based on its reported effectiveness, I decided to take a chance and buy a few. These plates are gargantuan in size (roughly 3’ by 5’) and quite cumbersome to maneuver singlehandedly - two of the plates I purchased weighed 65 pounds each, and the other two plates I purchased weighed 80 pounds each (FYI, I did actually weigh them). This posed a significant challenge when it came to measuring their acoustic effect in the room, since I didn’t want to permanently mount them until I knew where they would yield the best results. However, if not mounted or physically held against a wall by a human being, they would topple onto the floor. But having people hold the Modex in place during a measurement would skew the frequency response, making it difficult to isolate the effect of the treatment from the effect of the bodies in the room. I needed the room to be vacant, but I also didn’t want to have to put a ton of holes into my walls while experimenting with where these plates should go. So I put my thinking cap on. And then I got out the chop saw.

The plan was to lay a couple of boards on the floor in order to raise the plate above the floor trim, thus allowing it to be pressed evenly flush against the wall. Then to prevent the plate from tipping over, I’d use non-slip pads and pieces of 2 x 4 with the ends cut at a 45 degree angle to hold the Modex in place, and they would in turn be held in place by dumbbells. The plates were said to be most effective where boundary surfaces intersect (e.g. room corners), so I focused my efforts in the rear corners, as features of the room made that the only viable option for symmetrical positioning of these behemoths.

Success! I tested each plate type accordingly. Then I realized I also needed to measure all 4 plates together, in order to assess their collective influence.

Great. But I also needed to measure how the plates would perform when placed closer to the ceiling.

And of course, all 4 plates near the ceiling at one time.

Brilliant! I was now ready to commit to placements for 2 of the plates. As for the others, the jury was still out. What if I tried putting them on the actual ceiling? How could I accomplish that without actually permanently mounting them? Hmmmm. I’ll place speaker stands on top of plant stands that have an adjustable height via a rotating top. The speaker stands have a wider base than the plant stands, so I’ll use a sheet of plywood as a medium between the two. Then with the help of an assistant, we’ll rotate the top of the plant stand until the Modex is firmly wedged into the ceiling.

Boom baby! I admit that was rather unsafe. Definitely do not try this at home - one error in judgement, and 80lbs will fall right on top of you - it will not be pretty. But if you’re as psychotic as me, you’ll realize that the only way to get the answers you need is to proceed accordingly (and cautiously). Ultimately, a comparison of all the various measurements showed the best results came from this arrangement:

The Modex Plates are sitting on custom-made wood platforms, and the top of the plates are held flush against the wall by 1" L brackets that I installed into the ceiling joists. This was an easier method of mounting than that suggested by the manufacturer, and it allowed me to position the plates right up against the ceiling / wall boundary (which would not have been possible using the mounting brackets that came with the plates). The other side of the room has a baseboard radiator, so at my wife’s suggestion we installed a permanent shelf into that wall.

That’s pretty sexy. Now on to testing my other acoustic treatment. This absorption and diffusion functions by engaging sound as it is in motion, a design that requires an air gap between the treatment and the surface behind it. As you change the size of the air gap, you change how the treatment performs. Similarly, as you change the thickness of a panel, you change its effective range. So I did an extensive trial of testing, using 6’ columns, 4’ columns, and 2’ columns at every given location, with air gaps between 0” and 5”. I also tested panel thicknesses between 2" and 6", and compared different types of absorption and diffusion. And I tested the treatment free-standing directly on the floor, and at various distances off the floor using wood platforms. If you can think of it, I probably tried it.

With myriad measurements in hand, I eventually settled on the following configuration for the rear side walls:

When it came to the front corners of the room where the subs are located, I concocted a framework of platforms that allowed me to stand treatment on top of the subwoofers.

Then I tested various configurations before making a final decision. Here are some examples that didn't make the cut:

Ultimately, a diffusion panel 2” from the front wall and 4” from the side wall yielded the best results (as to why those specific distances were best, or why diffusion instead of absorption, I have no idea…all I know is it measured best this way).

In the old room, I had many layers of this treatment (made by Real Traps), which collectively consumed a great deal of the available free space. In the new room, the independent positioning of the speakers / subs / listener along with the utilization of the Modex Plates (which are less invasive due to their flush mounting), resulted in needing to use a little less than half of the prior acoustic treatment. Which means, I have more space in the room now. Which means, it’s time to dance.

For those wondering, the black and white panels depicted in these images do different things. The black panels absorb low to high frequencies, and the white panels absorb low frequencies only. I had them colored this way when I bought them so that I would be able to easily distinguish each type. Any perceived color coding of the room is completely accidental - things just happened to work out in the way that they did.

As for the ceiling, the two panels above the speakers (and those to the left and right on the side wall / window) are absorbing the 1st reflection points between the main speakers and listener. Another 2 panels on the rear ceiling took care of a ringing that would have interfered with recording a vocal or instrument in the room. Then I placed some small diffusor squares around, which had a subtle but positive effect on the room's high frequency response. FYI, the blue lines in the following image are chalk markings - left to right indicates the location of ceiling joists, and front to back frames the center of the ceiling.

The last step was to dial in some corrective parametric EQ for the icing on the cake. For the audio novices among us, EQ is short for equalization, which is a process that is used to modify the sonic characteristics of an audio recording. With respect to room acoustics, the sonic characteristics of a speaker can be adjusted using EQ, so as to offset certain features of the room - for example, if the room is creating excessive energy at 70Hz, EQ can be applied to reduce the amount of 70Hz before the sound comes out of the speaker in order to compensate for the room’s effect, thereby creating a balanced sound at the listening position. One of the beautiful things about Genelec’s digital line of speakers (in this case, a pair of 8260s and a pair of 7270s) is that each speaker individually contains a comprehensive set of EQ filters that can be independently adjusted and fine tuned with precision. Such corrective EQ can be quite beneficial, particularly when dealing with smaller rooms where it can be impractical or impossible to address certain anomalies any other way. Indeed, if acoustic treatment is a butcher’s knife, EQ is a scalpel.

You might be wondering though, if we can just EQ the speakers to compensate for the room, then why was this entire acoustic treatment fiasco even necessary? The answer is that EQ by itself is insufficient for the task: A) it cannot compensate for nulls in the frequency response, which is where sound reflections cancel each other out, therein creating a void or “hole” in the audio, and B) in an untreated room, the frequency response can vary greatly as you move within the room, thus rendering any EQ adjustments only relevant to a narrow listening position. So you need to address as much as possible using acoustic treatment first, before moving on to consider corrective EQ measures.

With everything said and done, and around 250 measurements later, the new room sounds phenomenal. A couple of tissues taped to the ceiling to diffuse the light, and this studio is officially a wrap. Yes, it was all worth the effort. And now that the studio is finally finished, I can begin making some music again. Well, at least until the next studio escapade!!!!

UPDATE 8/12/15: There has been one more important addition to the studio - see here.

The ingenuity to calibrate your room yourself is remarkable. The only thing I wonder is was it overkill, to put yourself through such work & physical risk?

It seems that the most optimal positioning of your Modex panels was the result of relative observations - that is, you compared one response to another, and the frequency responses that came out the best in comparison to the others were the ultimate positions for the panels. I would assume that the 2x4's themselves would also obscure the frequencies a bit, though certainly not to the degree that people holding up the panels would. But at the end of the 2x4 trials of holding the panels up, you picked the configuration that was relatively better than the rest of them.

So, if that was the case (so long as I'm not missing something), could you not have had people hold up the panels instead? Yes they would have obscured the responses, but they would have done so in every single one of the configurations you trialed, thus canceling out the effect (so long as the same individual held up the same panel in the same position each time). You would still have seen the same relatively best response that you saw with the 2x4's, and EQ'ing following the treatment would have still been consistent.

Either way, glad it worked out in the best outcome possible. Looking forward to your next release(s).

Yes, the final positioning of the Modex were determined by comparing the relative frequency responses of each possible placement configuration, including that of no treatment. Technically speaking, the 2X4’s used to hold the Modex in place during testing may have done something to the measured frequency response - however, to the degree that they did anything, it was negligible. I can say this with certainty because after I committed to the Modex placement and removed the 2X4’s, I remeasured the room to confirm that the absence of the 2X4’s did not alter the response in any appreciable way (which they didn’t). I do not expect this would have been the case if the 2X4’s were replaced with human bodies.

Regardless, if people were holding up the Modex panels during the testing, then provided they remained standing in the exact same position while the Modex moved from position to position, then you could do a relative comparison between the Modex’s various positions in the room. However, you would still need to know what effect the people were having on those measurements in the first place. If there were commonalities between all the measurements, for example the same degree of absorption between 200 and 400 Hz, then you would want to know whether it was the human bodies doing that or whether the Modex were achieving that at each given position….if there were no commonalities between all the measurements, then you would have absolutely no idea how the human body was contributing to the response.

Either way, you would end up choosing the best measurement relative to each other (and relative to no treatment whatsoever), and after installing the Modex you would have to remeasure with no people in the room to confirm the measurement, and then hope the absence of human bodies did not change the response such that you no longer preferred that orientation. And if you no longer preferred that orientation, then you would have to analyze the difference between that particular setup with and without bodies, and from there try to extrapolate / predict what effect the absence of bodies would have in the other alterantive setups that were measured with bodies in the room, and then commit to one of those and measure to confirm.

I cannot even express how much I'm looking forward to a new song/album. I can already pretty much recite word for word all of the lyrics in Ronin and The Way. I don't care if its badass like Ronin, theatrical (but still pretty badass) like The Way, or something totally new.

Of course, it sounds like you don't want to put any date/expectations on it, so I'll be patiently waiting for awesomeness, thinking about how much better my mansion full of trees is than the city of my dreams.

Love the music that you make. I recently had to write an essay for my AP English Literature class where we take a modern poem, compare it to "classic" poems, and explain why the modern one should be taught in English classes.

Of course, I chose your song "The Way". I would love to share it with you and see your thoughts. Your lyrics, as well as the ones I compare yours to are all at the very bottom of the document. It would be best to read them first. I hope you enjoy it, and would love to see what you think!

A very interesting essay, in which you make a compelling argument for the utilization of modern works in English class. I would agree that there is a disconnect between old classics and modern times, in the minds of students. As you mention, it is not that the ideas expressed in old classics are outdated or invalid, but simply that the manner in which those ideas are expressed - the grammar / execution - is outdated. To be clear, this does not mean old classics should be abandoned, nor that their construction is without value to students; but it should be balanced alongside modern works. I also think the strategy of examining old and modern works with similar themes, both in isolation and comparatively, is a very effective model, one likely to enhance a student’s understanding and appreciation of older works.

That being said, I do think comparing a poem intended to be read on paper, with song lyrics intended to be heard, can be tricky - the way in which lyrics are recited, and the musical context in which they occur, can both contribute to their meaning. So divorcing song lyrics from the song itself may run the risk of undermining their potency. I’m not saying this is necessarily the case with “The Way”, although if I had been writing those words with the final destination being paper (rather than audio), the resulting form / structure would very likely have been different. So this is food for thought.

Lastly, I would just point out that the meaning of “not the right way” is ambiguous - it can be interpreted as my criticism of society (as you state), but it can also be interpreted as society’s criticism of me. It’s also worth considering there is a difference between saying something is the right way for me, and saying something is the right way for everyone…you have interpreted my statements in the verse as claiming the latter. So I simply mention this for your consideration.

Thank you for taking the time to respond! I really appreciate that you took the time to do this and really gave it some good thought, too.

The part you mention about separating the lyrics from the song is very interesting to get the artist's perspective. It's definitely worth mentioning the energy of the music when talking about song lyrics.

I never thought of interpreting "not the right way" as society's criticism on you, and it's certainly interesting to think of it that way. In some ways, the two ways two interpret it by default go hand in hand a bit. If you deviate from society, naturally you and society will both be critical of each other. However, as you state, it does not necessarily mean that you think the right way for you is the right way for everyone.